(1) Field of the Invention
The present invention relates to a display device and, in particular, to a high-resolution liquid crystal display device.
(2) Description of the Related Art
In liquid crystal devices, a TFT substrate on which pixels each including a pixel electrode, and a thin film transistor (TFT), for example, are arranged in a matrix and a counter substrate are arranged to be opposed to each other. A liquid crystal is sandwiched between the TFT substrate and the counter substrate. A transmittance of light of liquid crystal molecules is controlled on a pixel-by-pixel basis, thereby an image is formed.
One of problems of the liquid crystal display devices is viewing angle characteristics. An IPS (In Plane Switching) liquid crystal display device rotates the liquid crystal molecules by an electric field parallel to the substrates to control the light transmittance of the liquid crystal, and is excellent in viewing angle characteristics. Meanwhile, the resolution of the liquid crystal display devices, in particular, small and medium-sized liquid crystal display devices is increasing.
With the increase of the resolution, a ratio of an area of a diameter of a through hole for allowing the pixel electrode to come in contact with a source electrode of the TFT, formed on the TFT substrate side, to an entire area of a pixel is also increased. Japanese Unexamined Patent Application Publication No. 2014-146039 describes a structure of the through hole in the IPS liquid crystal display device.